v4.19.13 snapshot.
diff --git a/arch/arc/kernel/troubleshoot.c b/arch/arc/kernel/troubleshoot.c
new file mode 100644
index 0000000..e8d9fb4
--- /dev/null
+++ b/arch/arc/kernel/troubleshoot.c
@@ -0,0 +1,242 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ */
+
+#include <linux/ptrace.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/kdev_t.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/debug.h>
+
+#include <asm/arcregs.h>
+#include <asm/irqflags.h>
+
+/*
+ * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
+ * -Prints 3 regs per line and a CR.
+ * -To continue, callee regs right after scratch, special handling of CR
+ */
+static noinline void print_reg_file(long *reg_rev, int start_num)
+{
+ unsigned int i;
+ char buf[512];
+ int n = 0, len = sizeof(buf);
+
+ for (i = start_num; i < start_num + 13; i++) {
+ n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
+ i, (unsigned long)*reg_rev);
+
+ if (((i + 1) % 3) == 0)
+ n += scnprintf(buf + n, len - n, "\n");
+
+ /* because pt_regs has regs reversed: r12..r0, r25..r13 */
+ if (is_isa_arcv2() && start_num == 0)
+ reg_rev++;
+ else
+ reg_rev--;
+ }
+
+ if (start_num != 0)
+ n += scnprintf(buf + n, len - n, "\n\n");
+
+ /* To continue printing callee regs on same line as scratch regs */
+ if (start_num == 0)
+ pr_info("%s", buf);
+ else
+ pr_cont("%s\n", buf);
+}
+
+static void show_callee_regs(struct callee_regs *cregs)
+{
+ print_reg_file(&(cregs->r13), 13);
+}
+
+static void print_task_path_n_nm(struct task_struct *tsk, char *buf)
+{
+ char *path_nm = NULL;
+ struct mm_struct *mm;
+ struct file *exe_file;
+
+ mm = get_task_mm(tsk);
+ if (!mm)
+ goto done;
+
+ exe_file = get_mm_exe_file(mm);
+ mmput(mm);
+
+ if (exe_file) {
+ path_nm = file_path(exe_file, buf, 255);
+ fput(exe_file);
+ }
+
+done:
+ pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
+}
+
+static void show_faulting_vma(unsigned long address, char *buf)
+{
+ struct vm_area_struct *vma;
+ char *nm = buf;
+ struct mm_struct *active_mm = current->active_mm;
+
+ /* can't use print_vma_addr() yet as it doesn't check for
+ * non-inclusive vma
+ */
+ down_read(&active_mm->mmap_sem);
+ vma = find_vma(active_mm, address);
+
+ /* check against the find_vma( ) behaviour which returns the next VMA
+ * if the container VMA is not found
+ */
+ if (vma && (vma->vm_start <= address)) {
+ if (vma->vm_file) {
+ nm = file_path(vma->vm_file, buf, PAGE_SIZE - 1);
+ if (IS_ERR(nm))
+ nm = "?";
+ }
+ pr_info(" @off 0x%lx in [%s]\n"
+ " VMA: 0x%08lx to 0x%08lx\n",
+ vma->vm_start < TASK_UNMAPPED_BASE ?
+ address : address - vma->vm_start,
+ nm, vma->vm_start, vma->vm_end);
+ } else
+ pr_info(" @No matching VMA found\n");
+
+ up_read(&active_mm->mmap_sem);
+}
+
+static void show_ecr_verbose(struct pt_regs *regs)
+{
+ unsigned int vec, cause_code;
+ unsigned long address;
+
+ pr_info("\n[ECR ]: 0x%08lx => ", regs->event);
+
+ /* For Data fault, this is data address not instruction addr */
+ address = current->thread.fault_address;
+
+ vec = regs->ecr_vec;
+ cause_code = regs->ecr_cause;
+
+ /* For DTLB Miss or ProtV, display the memory involved too */
+ if (vec == ECR_V_DTLB_MISS) {
+ pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n",
+ (cause_code == 0x01) ? "Read" :
+ ((cause_code == 0x02) ? "Write" : "EX"),
+ address, regs->ret);
+ } else if (vec == ECR_V_ITLB_MISS) {
+ pr_cont("Insn could not be fetched\n");
+ } else if (vec == ECR_V_MACH_CHK) {
+ pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
+ "Double Fault" : "Other Fatal Err");
+
+ } else if (vec == ECR_V_PROTV) {
+ if (cause_code == ECR_C_PROTV_INST_FETCH)
+ pr_cont("Execute from Non-exec Page\n");
+ else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
+ pr_cont("Misaligned r/w from 0x%08lx\n", address);
+ else
+ pr_cont("%s access not allowed on page\n",
+ (cause_code == 0x01) ? "Read" :
+ ((cause_code == 0x02) ? "Write" : "EX"));
+ } else if (vec == ECR_V_INSN_ERR) {
+ pr_cont("Illegal Insn\n");
+#ifdef CONFIG_ISA_ARCV2
+ } else if (vec == ECR_V_MEM_ERR) {
+ if (cause_code == 0x00)
+ pr_cont("Bus Error from Insn Mem\n");
+ else if (cause_code == 0x10)
+ pr_cont("Bus Error from Data Mem\n");
+ else
+ pr_cont("Bus Error, check PRM\n");
+#endif
+ } else if (vec == ECR_V_TRAP) {
+ if (regs->ecr_param == 5)
+ pr_cont("gcc generated __builtin_trap\n");
+ } else {
+ pr_cont("Check Programmer's Manual\n");
+ }
+}
+
+/************************************************************************
+ * API called by rest of kernel
+ ***********************************************************************/
+
+void show_regs(struct pt_regs *regs)
+{
+ struct task_struct *tsk = current;
+ struct callee_regs *cregs;
+ char *buf;
+
+ buf = (char *)__get_free_page(GFP_KERNEL);
+ if (!buf)
+ return;
+
+ print_task_path_n_nm(tsk, buf);
+ show_regs_print_info(KERN_INFO);
+
+ show_ecr_verbose(regs);
+
+ pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n",
+ current->thread.fault_address,
+ (void *)regs->blink, (void *)regs->ret);
+
+ if (user_mode(regs))
+ show_faulting_vma(regs->ret, buf); /* faulting code, not data */
+
+ pr_info("[STAT32]: 0x%08lx", regs->status32);
+
+#define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
+
+#ifdef CONFIG_ISA_ARCOMPACT
+ pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
+ (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
+ STS_BIT(regs, DE), STS_BIT(regs, AE),
+ STS_BIT(regs, A2), STS_BIT(regs, A1),
+ STS_BIT(regs, E2), STS_BIT(regs, E1));
+#else
+ pr_cont(" : %2s%2s%2s%2s\n",
+ STS_BIT(regs, IE),
+ (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
+ STS_BIT(regs, DE), STS_BIT(regs, AE));
+#endif
+ pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
+ regs->bta, regs->sp, regs->fp);
+ pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
+ regs->lp_start, regs->lp_end, regs->lp_count);
+
+ /* print regs->r0 thru regs->r12
+ * Sequential printing was generating horrible code
+ */
+ print_reg_file(&(regs->r0), 0);
+
+ /* If Callee regs were saved, display them too */
+ cregs = (struct callee_regs *)current->thread.callee_reg;
+ if (cregs)
+ show_callee_regs(cregs);
+
+ free_page((unsigned long)buf);
+}
+
+void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
+ unsigned long address)
+{
+ current->thread.fault_address = address;
+
+ /* Show fault description */
+ pr_info("\n%s\n", str);
+
+ /* Caller and Callee regs */
+ show_regs(regs);
+
+ /* Show stack trace if this Fatality happened in kernel mode */
+ if (!user_mode(regs))
+ show_stacktrace(current, regs);
+}